Developmental Psychology Chapter 2: Theory and Research PDF

DEVELOPMENTAL PSYCHOLOGY Chapter 2: Theory and Research Prepared by: Camille Faye Elcano-de la Paz, RPm  TOPICS Chapter 3: Forming a New Life Conceiving New Life Mechanisms of Heredity...

DEVELOPMENTAL PSYCHOLOGY Chapter 2: Theory and Research Prepared by: Camille Faye Elcano-de la Paz, RPm  TOPICS Chapter 3: Forming a New Life Conceiving New Life Mechanisms of Heredity Influences of Heredity and Environment Prenatal Development Monitoring and Promoting Prenatal Development MA DE BY Cfelcano Quiz 2 : 15 items DEVELOPMENT STARTS AT CONCEPTION Conception / Fertilization - union of the sperm and ovum which produces a zygote or a one-celled organism  MONOZYGOTIC VS. DIZYGOTIC TWINS Monozygotic Twins Dizygotic Twins Result from the cleaving of one Fraternal twins; result of two fertilized egg and genetically separate eggs being fertlized by identical. two different sperms to form 2 Note: They can still differ outwardly unique individuals because of the interaction Can be the same or different between genes and environmental sex influences Result of multiple eggs being released at one time. Monozygotic Twins Dizygotic Twins MECHANISMS OF HEREDITY The genetic transmission of heritable characteristics from parents to offspring. Genetic Code DNA Bases Chromosomes  DNA (Deoxyribonucleic Acid) GENETIC Chemical that carries inherited instructions for the development of all cellular forms of life. Double helix structure; made of pairs and bases CODE Contains genes Sequence of bases within Bases the DNA molecule; The “Letters” of the genetic code governs the formation of Adenine, Thymine, Cytosine, Guanine proteins that determine the structure and Chromosomes functions of living cells. Coils of DNA that contains genes Every cell (except sex cells) contains 23 pairs aof chromosomes - 46 in total  Meiosis Mitosis cell division of sex cells cell division of non-sex Note: there is a cells (autosomes) random exchange of genes and alleles Could be good, bad or neutral MUTATION Are permanent alterations in genetic materials Result when a mistake in copying the chromosome is made WHAT DETERMINES SEX? It is the father’s sperm that genetically determine a child’s sex Father’s sperm contains X (female) and Y (male)  Sex Chromosomes Autosomes The 23rd pair (XX or XY) that givern the baby’s sex The 22 pairs that are not related Remember that every ovum is to sexual expression an X chromosome, only the father’s sperm may contain the X or Y  Alleles Genes that can produce PATTERNS OF alternative expressions of characteristic GENETIC Alternate versions of the same gene TRANSMISSION We receive one maternal and one paternal allele for any given trait, which could be homozygous (RR/rr) or heterozygous (Rr/rR)  Dominant Inheritance When a child receives different alleles, PATTERNS OF only the dominant one is expressed. Regardless if the allele is homozygous GENETIC or heterozygous TRANSMISSION Recessive Inheritance The child receives identical recessive alleles, resulting in the expression of a nondominant trait (rr only)  Phenotype An expression of a genotype The observable characteristics of a person through which the genotype is expressed PATTERNS OF The product of the genotype and environmental influences GENETIC Genotype TRANSMISSION Genetic makeup of a person, containg bothe expressed and unexpressed characteristics The hidden alleles float around undetected for generations and be expressed if both parents carry a hidden copy.  Multifactorial Transmission Environmental experiences modifies the expression of a gentype; illustrates the interaction of anture ans nurture and how they affect outcomes. Epigenesis PATTERNS OF Explains why identical twins are not exactly the GENETIC same Mechanisms that turns genes on or off and TRANSMISSION determines functions of body cells. How? The chemical molecules attached to the gene that alter the way a cell reads the gene’s DNA. Environmental factor can cause epigenetic changes. Cells are particularly susceptible to epigenetic modification during critical period such as puberty and pregnancy. GENETIC AND CHROMOSOMAL ABNORMALITIES Dominance or Recessive Inheritance of Defects Defects transmitted by dominant inheritance are less likely to be lethal at an early age than those transmitted by recessive inheritance because any affected children would likely to die before reproducing. Recessive defects are expressed only if the child is homozygous for that gene. GENETIC AND CHROMOSOMAL ABNORMALITIES Sex-Linked Inheritance of Defects Certain characteristics carried on the X inherited from the mother are transmitted differently to her male and female offspring. Y chromosome is smaller and carries far fewer genes than the X chromosome. If a woman has a “bad” copy of a particular gene, she has a backup copy, However, if a male has a “bad” copy of a particular gene, that gene will be expressed. If heterozygous female carry one bad copy of a recessive gene and one good copy are called CARRIERS GENETIC AND CHROMOSOMAL ABNORMALITIES Chromosomal Abnormalities Typically occur because of errors in cell division, resulting in extra or missing chromosome The likelihood of errors increase in offsprng of women age 35 or older. GENETIC AND CHROMOSOMAL ABNORMALITIES Down Syndrome Trisomy 21; extra chromosome 21 most common chromosomal abnormality accounts for 40% of all cases of moderate to severe mental retardation DOWN SYNDROME  Clinical service that GENETIC advises prospective parents of their probable COUNSELING risk of having children with hereditary defects. AND TESTING At risk: Family history of hereditary illness Came from ethnic groups at higher risk of passing oon genes for certain diseases  STUDYING HEREDITY AND ENVIRONMENT Behavioral Genetics Heritability Inborn traits or Totality of nonhereditary or characteristics inherited experiential, influences on from biological parents development. Heredity and genes Starting with the prenatal Nature environment in the womb and continuing throughout life Environment Nurture HOW HEREDITY AND ENVIRONMENT WORK TOGETHER? Nowadays, developmental scientists see heredity and environment as a part of a complex deelopmental system - combination of constitutional factors (biology and psychology) and social, economic, and cultural factors help shape development  ex. Height has genetic limits; we don’t see REACTION RANGE people who are only 1 foot Refers to range of potential expressions tall or who are 10 feet tall. of a hereditary trait. Body size for example, depends largely on biological process, which are genetically regulated. Heredity can influence whether reaction range is wide or narrow  but.. Cognitions and Personality are NOT highly CANALIZATION canalized as they are highly canalized traits such as eye more subject to variations color, are strongly programmed by in experience. genes, and there is little opportunity for variance in their expression. Traits that are important to survive, such as talking and walking, tend to be highly canalized. GENOTYPE-ENVIRONMENT INTERACTION Similar children often develop differently depending on their home environments ex. Many children are exposed to pollen and dust, but those with a genetic predisposition are more likely to develop allergic reactions GENOTYPE-ENVIRONMENT CORRELATION It is the tendency of certain genetic and environmental influences to reinforce each other. It works in 3 ways to strengthen the phenotypic expression of genotypic tendency. 1.) Passive Correlations 2.) Reactive / Evocative Correlations 3.) Active Correlations  Passive Correlations Parents, who provide the genes that predisposes a child towars a trait, also tend to provide an environment that encourages the GENOTYPE development of that trait. Function ONLY when the child is living with a ENVIRONMENT biologically related parent. ex. A musical parent is likely to create a home CORRELATION environment in which music is heard regularly, to give a child music lessons, and take the child to musical events. If the child inherited the parent’s musical talent, the child’s musicality will reflect a combination of genetic and environmental influences.  Reactive or Evocative Correlation Children with differing genetic makeups GENOTYPE evoke different reactions from others - other people react to the child’s genetic ENVIRONMENT make up. CORRELATION ex. Parents who are not musically inclined may make a special effort to provide musical experiences for a child who shows interest and ability in music.  Active Correlation As children get older and have more freedom to choose their own activities and environments, they actively select or create GENOTYPE experiences consistent woth their genetic ENVIRONMENT tendencies. Active correlations involve individuals CORRELATION actively selecting and seeking out environments that are compatible with their genetic predispositions or interests. ex. seek out musical friends, take music classes or take a music-related degree.  Siblings can differ greatly in intellect and personality. It could be due to genetic differences, which lead children to need NON-SHARED different kinds of stimulation or to respond differently to a similar home environment. ENVIRONMENT Children may live in the same family, but that does not mean that their experiences are identical ex. different experiences of the eldest, middlea nd youngest child - thus the influences are not identical.  Obesity CHARACTERISTICS 40% to 70% from genetic INFLUENCED BY Environmental experiences may also contribute HEREDITY AND Temperament and Personality ENVIRONMENT Temperament is largely inborn and relatively consistent over the years Intelligence Heritability is around 40%. Heredity exerts strong influence on general intelligence Schizophrenia Experience also influences intelligence, an Heritability range is 60-80% enriched or impoverished environment can But monozygotic twins are not always substantially affect the development and concordant for scizophrenia, perhaps due to expression of innate ability. epigenetic process  Gestation Gestational Age Period between conception and birth. Age of an unborn baby, 38 weeks to 40 weeks usually dated from the first (266-280 days) day of an expectant 28weeks - viable - 50% mother’s last menstrual chance of survival cycle.  2 Principles of Development Cephalocaudal Proximodistal “Head to Tail” “Near to Far” Development proceeds Development proceeds from the head to the lower from parts near the center part of the trunk of the body to outer ones. An embryo’s head, brains The head and trunk develop and eyes develop earliest before the limbs, and the and are disproportionately arms and legs before the large until the other parts finger and toes. catch up  Germinal Stage Fertilization to 2 weeks STAGES OF Embryonic Stage DEVELOPMENT 2 to 8 weeks Fetal Stage 8 weeks to birth  The zygote divides, become more complez and is implanted in the wall of the uterus. 36 hours after fertilization - rapid motosis occurs 72 hours after - 16-32-64 cells GERMINAL While dividing and travelling to the uterus, its form changes into a blatocyst - a fluid-filled sphere STAGE Blastocyst - consist of inner mass of cells that will eventually develop into the embryo. Implantation of the blastocyst occurs at about day 6 Thropoblast - is an outer layer of cells that provides nutrition and support for the embryo  Amniotic Sac GERMINAL A fluid-filled membrane that encases the developing embryo, protecting it and giving it room to move and STAGE grow Placenta Other parts of the Allows oxygen, nourishmentm and wastes to pass blastocyst begin to between mother and embryo develop into organs produces hormones that support pregnancy, prepare that will nurture and the breast for lactation, and eventually stimulate uterine contractions protect the development in the Umbilical Cord womb. Connects the embryo - connection of the mother and baby  The organ and major body systems - respiratory, digestive and nervous sytem - develop rapidly through organogenesis EMBRYONIC Critical period when the embryo is most vulnerable to teratogens STAGE Brain growth and development begins Spontaneous Abortion Miscarriage, a natural expulsion from the uterus of an embryo that cannot survive outside the womb. it is called still birth if it occurs after 20weeks of gestation  The appearance of the first bone cell signals this stage The fetus grows rapidly to about 20 times its previous length, and organs and body FETAL systems become more complex. Most seem to have innate taste preferences STAGE to sweet foods, and preferences for bitter or specific taste are more variable Fetuses respond to the mother’s voice and heartbeat and the vibrations of her body Fetuses recognize their mother’s voice, they prefer it over other women’s and their father’s ENVIRONMENTAL INFLUENCES: MATERNAL FACTORS TERATOGEN An environmental agent, such as virus, a drug or radiation, that can interfere wirh normal prenatal development and cause developmental abnormalities. First trimester as the most risky period. ENVIRONMENTAL INFLUENCES: MATERNAL FACTORS 1.) Nutrition and Maternal Weight Desirable weight gain depends on BMI before pregnancy. Current recommendations: Underweight - plus 28 to 40 pounds Normal weight - plus 25 to 40 pounds Overweight - plus 15 to 25 pounds Obese - plus 11 to 20 pounds What mother eats is also important - Folic Acid ENVIRONMENTAL INFLUENCES: MATERNAL FACTORS 2.) Malnutrition It can result in fetal growth restriction and low birth weight It affects the mother, the baby and even the next generation. Fetal undernutrition has been associated with schizophrenia, increased risk of diabetes, and overweight/obesity in adulthood. ENVIRONMENTAL INFLUENCES: MATERNAL FACTORS 3.) Physical Activity and Work Moderate exercises do not endanger the fetus of healthy women employment during pregnancy generally entails no special hazards Contact sports or activites that might result in fall should be avoided. Strenous working conditions, occupational fatigue, and long working hours may be associated with greater risk of premature birth. ENVIRONMENTAL INFLUENCES: MATERNAL FACTORS 4.) Drug Intake Medical Drugs No medication should be taken by a pregnant or breastfeeding woman unless it is essential for her health or her child’s and that care be taken in choosing the safest drug available. ENVIRONMENTAL INFLUENCES: MATERNAL FACTORS 4.) Drug Intake Opioids Alcohol Nicotine CAffeine Marijuana Cocaine Metamphetamine ENVIRONMENTAL INFLUENCES: MATERNAL FACTORS 5.) Maternal Illness AIDS Rubella Toxoplasmosis Diabetes  ENVIRONMENTAL INFLUENCES: MATERNAL FACTORS 6.)Maternal Anxiety and Depression Associated with more active and irritable temperament in newborns , inattentiveness (8 months), and negative emotionality or behavioral disorders in early childhood Depressed mothers are more likely to have premature birth, child is developmentally delayed, violent and antisocial behaviors in adolescence  ENVIRONMENTAL INFLUENCES: MATERNAL FACTORS 7.) Maternal Age The chance of miscarriage or still birth rises with maternal age. There is a higher risk of premature delivery, retarded fetal growth, birth defects and chromosomal abnormalities such as Down Syndrome.  ENVIRONMENTAL INFLUENCES: MATERNAL FACTORS 8.) Outside Environmental Hazards Such as air pollution, chemicals, radiation, extremes of heat and humidity, high concentration of disinfeection, by-products, insecticides, toxins, (eg. lead, mercury, etc.)  MONITORING AND PROMOTING PRENATAL DEVELOPMENT Noninvasive Procedures Prenatal Blood Ultrasound Cell-Free Tests DNA  Amniocentesis A sample of amniotic fluid is withdraws MONITORING AND Chorionic Villus Sampling PROMOTING Tissue from the membrane surrounding PRENATAL the fetus DEVELOPMENT: Embryoscopy Insertion of a tiny viewing scopre into the INVASIVE uterus PROCEDURES Umbilical Cord Sampling Allows direct access to fetal DNA in the blood vessels of the mbilical cord.